Ultra-large-scale integrated (ULSI) circuits may include more than one million electronic devices (e.g., transistors) that are formed on a semiconductor substrate, such as a silicon (Si) substrate, and cooperate to perform various functions within the device. Plasma etching is commonly used in the fabrication of transistors and other electronic devices. During plasma etch processes used to form transistor structures, one or more layers of a film stack (e.g., layers of silicon, polysilicon, hafnium dioxide (HfO2), silicon dioxide (SiO2), metal materials, and the like) are typically exposed to etchants, for example, halogen-containing etchant gases, such as hydrogen bromide (HBr), chlorine (Cl2), carbon tetrafluoride (CF4), and the like. Such processes cause a residue to build up on the surfaces of the etched features, etch masks, and elsewhere on the substrate.
To remove the residues from processed substrates an abatement process may be performed. Conventionally, the abatement process includes heating the processed substrate to a desired temperature while providing one or more process gases to promote the outgassing of residues from the substrate surface. The outgassed residues may then be purged from the chamber. In a typical chamber used to perform the abatement process, the one or more process gases are provided via one or more shower heads disposed within the chamber. When using a chamber comprising an overhead heat source (e.g. a radiant heat source located in a top portion of the chamber) the one or more shower heads must be placed and configured in a manner as to not interfere with the transmission of heat. However, in such configurations, the one or more shower head may fail to provide an even radial distribution of the process gases to the substrate surface, resulting in an uneven outgassing of residues, thereby failing to completely remove the residues from the substrate uniformly.
Therefore, there is a need for an improved apparatus for the delivery of gas into a process chamber.